Extending the Design Space of Class E Mode to Design a Multi-Octave Power Amplifier

This brief presents a new extended continuum of class E (ECCE) mode for multi-octave power amplifier (PA) design. The impedance space of class E mode is expanded by considering the resistive component in the second harmonic impedance. This provides an overlap between the fundamental and second harmonic loads, which is for the first time explored for class E mode, enabling its design beyond the octave band. This mode offers a wide impedance range for the third harmonic termination, unlike a fixed point (open/short) in other extended continuous modes. This wide third harmonic design space provides high flexibility to design output matching. To verify the validity of the proposed mode, a PA has been designed using a 10W GaN HEMT CGH40010F from Wolfspeed. A design scheme is also presented to obtain the feasible matching loads at desired frequencies. The PA operates over a multi-octave band from 0.45-2.9 GHz, corresponding to the fractional bandwidth of 146.27%. This circuit provides drain efficiency of 60-72.9% and the output power between 39.6-41.7 dBm over the operating band.